1. Field of the Invention
The present invention relates to an electrical connector, and particularly to a high density backplane connector in which contact engaging portions of a male connector are arranged in first and second columns, and while a mating intersection of a receptacle connector is also arranged in first and second columns corresponding to the second and first columns of the contact engaging portions, respectively.
2. Description of Related Art
Backplane connector is generally configured with a wafer on which about four contacts, say first, second, third and fourth contacts are arranged in a single plane. For explanation, the first contact will referred to the contact closer to a motherboard, while the fourth contact will be the contact most distant to the mother. Since those four contacts are generally arranged in right-angle, the overall length of those four contacts vary accordingly, i.e. the first contact has the shortest overall length, while the fourth contact has the longest overall length. As a result, a single skew will be encountered. The same applies to a differential pairs are well since the contact lengths are different from each other within the pairs when it is arranged in right-angle.
The right angle configuration of the typical backplane connector provides variable lengths in signal transmission paths. The paths go from shortest to longest as contacts move further away from the component side of the daughter board. Signal launched at the same time would arrive at different times at the far end of the connector due to the difference in length, or skew, of the transmission paths. In a differential pair configuration, this difference in length, or skew, must be compensated for and is typically handled by the printed circuit board (PCB) designer. Some connectors are designed to provide skew compensation by adding air in the areas where the transmission paths bend on the longer path of the two paths within the differential pair. This allows the signal to travel faster around the bends of the longer path in an attempt to get the signals to arrive at the same time at the far end. The typical connector is described either in U.S. Pat. No. 7,229,318 issued to Winings et al. on Jun. 12, 2007 or U.S. Pat. No. 7,390,218 issued to Smith et al. on Jun. 24, 2008.
However, this method would have a detrimental effect impedance and increased crosstalk.